Thermosensitive recording materials, which include a thermosensitive recording layer on a base, such as paper or a plastic film, have been widely used as output sheets of facsimile machines, industrial measurement terminals, medical terminals, hand-held terminals, POS systems, and discovery systems.
In thermosensitive recording materials, in order to protect a thermosensitive recording layer from water, plasticizers, fats and oils, solvents, and the like, a protective layer is generally formed on the thermosensitive recording layer.
For example, (meth)acrylamide copolymer emulsions have been investigated as materials used for such a protective layer (see, for example, Patent Documents 1, 2, and 3). Although protective layers formed from these conventional (meth)acrylamide copolymer emulsions have high water resistance, solvent resistance, and heat resistance, the protective layers sometimes suffer from flex cracking, and there is room for improvement in the scratch resistance thereof.    [Patent Document 1] JP Patent No. 295630    [Patent Document 2] International Publication WO 2001/053108    [Patent Document 3] International Publication WO 2006/028111